The proposed research will use novel near infrared absorbance and fluorescence techniques to achieve rapid, specific detection and identification of biological molecules from laboratory or clinical isolates. Several components of the proposed research will involve the use of a laser diode near infrared spectrofluorometer (LDNIS), a highly efficient instrument which simultaneously records both absorption and emission spectra with an intracavity excitation optical configuration and fluorescence detector. The LDNIS can acquire absorbance down to 0.00001 AU and complete emission of low concentrations (subpicomolar). Near infrared fluorescence species can be detected selectively, taking advantage of the inherently low interference of near infrared absorbance and fluorescence. In this proposed study, the LDNIS will be used to explore identification procedures with near infrared fluorescence tagged antibodies specific for given antigens. We will develop a new method, which is less susceptible to interference, the near infrared dye immunoassay (NIRDIA). The proposed technique will be adaptable for immunoassays. We will develop the necessary instrumentation and assay configuration for both laboratory and field applicable NIRDIA. Increased sensitivity, specificity and ease of automation are the most important improvements we can achieve through the use of the proposed new chromogens. Due to the low detection limits using NIR fluorophores, the tagged antibody may be directly detected. The proposed study will utilize a synergistic union of two independently powerful new techniques, e.g., the LDNIS instrument and near IR chromogens.